D looks like the best answer
Answer: 
This is the same as 
All we're doing is adding 'a' and
since the term "sum" is the result of adding two or more numbers.
One quarter of a number is the same as dividing by 4.
Example: one quarter of 28 = 
Answer:
(3, 9)
Step-by-step explanation:
If we have ≤ or ≥, we use brackets to signify it includes the values.
If we have < or >, we use parenthesis to signify it doesn't include the values.
If they live at the same house and go to the same school then both, but if different house and school then with this info its impossible to know